Earth Science: Everyday Matter – Medicinal Drugs and Cosmetics
Today’s increasingly innovative medication plays a decisive role in preventing and treating diseases. More than 80 percent of the active ingredients in modern pharmaceuticals are generated chemically.
Although medicinal drugs do not guarantee eternal health, we still owe much to their role in our lives. Vaccines have eradicated polio in most of the world and people who are infected with HIV can delay the onset of AIDS by using medication.
With the aid of drugs, gastrointestinal ulcers are cured within a week, making surgery unnecessary and certain pharmaceutical agents called statins lower the cholesterol levels of people who are suffering from cardiovascular disease or considered at risk. Pharmaceutical companies have suggested that even the most advanced stages of cancer may someday be treatable by drug therapies.
The search for active ingredients
Every drug’s ability to help the body depends upon its active ingredient, such as a plant extract (whether of natural origin or generated genetically) -although active ingredients are increasingly chemical in nature. Because diseases are usually caused by invading viruses or by faulty interactions of the body’s molecules, researchers developing a new medicine first try to find a target associated with the disease, such as a body or viral molecule.
While directing the agent against this target, researchers try to discover what molecules might be bound to it. Researchers can test hundreds of thousands of different molecules by automated methods or study biomolecules that come into contact with the target molecule. They then try to duplicate its form and function, using computers to simulate the accumulation of molecules in the target.
When scientists have found the appropriate molecules, they conduct tests, for example to discover whether possible agents bind only to the target without affecting similar biomolecules (something that can cause a variety of undesired side-effects).
Extensive tests
Candidates for active ingredients are tested on cell cultures and animals so researchers can analyze how they change in the organisms, how they and the products of their decomposition are distributed, their levels of toxicity, and whether they damage an organisms’ genetic makeup. About three out of every four agents are rejected during these trials.
The remainder of these are used in clinical trials on human beings that test first the drug’s safety and then its effectiveness. Only one out of every 5,000 active ingredients discovered reaches the market. About 25 active ingredients are certified worldwide each year. The development of a new medicine takes an average of 12 years and costs about $800 million.
HOW SHAMPOO WORKS
The principal task of a shampoo is to clean the hair. For that purpose. shampoo contains surface-active substances, so-called surfactants. that become attached to the water-insoluble dirt and fat deposits in hair. Subsequently, they are washed away again with water.
However, fat removal from hair must not be too radical (normal soap is therefore unsuitable), because fatty substances in hair also have a protective function Beyond that, shampoos may also contain ingredients for various other effects, such as anti-dandruff agents fat replacement substances, enhancers. protein hydrolysates, and perfume oils.
ISSUES TO SLOVE
VACCINE CONCERNS At the center of the vaccination controversy often lie questions of effectiveness, the possibility of adverse side-effects and the age at which to recieve vaccinations.